Effect on Flat Surface Postural Stability Following Extended Durations on a Pitched Roof Setting

摘要

A total of 8,786 fatal work injuries were reported in 2001, one half of these fatal fall incidents were a result of falls from a pitched roof setting, as indicated by the Bureau of Labor Statistics. The Bureau of Labor Statistics indicated nearly 4,000 serious injuries were associated with industry related falls from roofs in 200 1. Previous roofing construction related research has focused on the changes on postural sway velocity as a result of decrements in one or more of the three major systems associated with balance (somatosensory, vestibular, and visual). Purpose of this study was to investigate the effect of exposure to a pitched roof setting on postural stability. All subjects who volunteered as participants (n=20; males,) were tested under three conditions: ten, twenty and thirty minute duration on a 12 x 15’ pitched roof segment to determine if there was a difference in sway velocity following various exposure durations. Data were collected over four, ten-second trials, under eyes open and eyes closed conditions. Performance was measured using the recordings made by the NeuroCom Balance Master@ System. Balance was recorded in sway velocity (degreesfsecond), where the value was representative of the change in center of gravity (COG) in the anterior, posterior, medial, or lateral directions. The angular change of the COG per unit time was summed and divided by ten-seconds to achieve an average sway velocity of the COG. The data were evaluated using 2 (eye) x 3 (duration) repeated measures analysis of variance (ANOVA). The analysis concluded that the average sway velocity of the COG resulted in a significant main effect at each level of duration (IO, 20,30 minute): pl0= .041, pZ0= .034, p30= .029. The findings have practical implications when dealing with the construction industry. On a daily basis, roofers ascend and conduct roofing related tasks for prolonged periods of time. Following exposure to the pitched roof setting, roofers must move from the roof to scaffolding or a ladder to descend. These findings suggest that there is a significant decrement in postural stability due to exposure to inclination. Postural stability is critical in ascending and descending ladders and scaffolding on flat surfaces. Possible areas of future research that might impact postural stability could potentially involve roof jacks, work boot design, and work rest cycles.